I started to number the new version "4.71" but as there are a number of new features (mainly thanks to George), I go to 4.80.
This version 4.80b1 is the evolution of 4.71b7.
Unless problem, it will be the final version 4.80.
It is likely that version 4.80 is the latest available for Windows XP and Mac OS X 10.6.
So that as many people can test this beta, it is available for Windows and macOS (recent versions) and for XP and 10.6.
For recent OS:WindowsmacOS

The P snap gets very uncertain if it is in an area with a lot of lines and objects – even if E, I & C are turned off, it won't always work – it either doesn't register at all, or it does register but doesn't draw the perpendicular exactly from the line it should do. You seem to need to go to an uncluttered area of the drawing to restore it.

In normal circumstances, in an uncluttered area, P works fine. But it does seem to preferentially draw a perpendicular from an end, intersection or centre – I thought that the intention was that you first made the P icon appear, then moved to E, C, or I to draw the perpendicular. But in use I have found that you really need to keep E, I & C turned off if you want to draw a normal perpendicular – or keep P turned off if you want to draw a (non-perpendicular) line from E, I or C. If this is the intention, then I just need to get used to it

And tangent seems to have got a bit difficult and uncertain too. Again, more so in an area with lots of objects to distract it.

And one thing that (I think) is not specific to 4.80 is that you can't draw an object from a centre (line, rectangle or oval/circle) from a centre of choice if the centre is somewhere inside a polygon (open or closed). It draws the object from the centre, but the centre is not where you chose to draw from. If you use Command Line, it looks like it's drawing it in the wrong place, but in fact gets it right when you complete the command line boxes. I seem to remember that this used to be a problem but got fixed ....?

Yes, with the new mode to do with the Perpendicular attraction, it is better to turn it on only when you want to draw a perpendicular line because as soon as RealCADD find a perpendicular attraction, now it stores it.
Perhaps it will be better to have two ways to do :
1) like before to draw sample perpendicular lines,
2) in two steps, if we want a perpendicular line with a specific object from a point which can be outside this object.

The 2 steps for 2) could be :
A) choose the perpendicular reference, for example by typing a key when a Perpendicular attraction is found on it, then the perpendicular reference could be highlighted,
B) move the mouse to choose the first point of the perpendicular line, at this step, the perpendicular attraction could be automatically off.

I see the bug when we draw an abject from center from the center of a polygon, thanks.

As far as I can tell, the new perpendicular system works really well on a simple drawing. But on a complicated drawing with lots of lines and objects in close proximity it seems to get confused.

Turning off P, to draw a non-perpendicular line from E, C or I works fine.

But it's drawing a perpendicular that seems to be the problem. Sometimes, even with E, I & C turned off, and only P active, it can't find a P at all, until I go to a different part of the drawing – or draw a new line and find a P on that.

And again even with E, I & C turned off, sometimes if it finds a P, it won't 'slide' along the line it is perpendicular to like it used to.

And sometimes it draws a perpendicular but not exactly from the line you are wanting to draw from. It's close but not exactly on it.

So yes, I think it would be better to restore the P snap to its old form – which works really well even on complicated drawings with lots of lines and objects close.

Are you sure it wouldn't be easier for drawing P from a specific point, just to have three more Snaps: P from E, P from C, and P from I. There are some spare shortcut letters left – perhaps F for "PE", K for "PC" and J for "PI". Or something like that. Or is that not possible/too cumbersome? Or is that in fact similar to what you are suggesting, just in two steps – I didn't quite understand what you meant?

I remember in the old ClarisCad you held the shift key down and selected the two snap icons you wanted (say Perpendicular AND Centre). With the shortcuts you could only do a single snap (Perpendicular OR Centre). But in Claris, the snaps couldn't be left turned on in the same way as in RealCADD. You could keep one on by double-clicking its icon, but that only lasted if you also double-clicked the icon for what you were drawing (say Line), so it wasn't anywhere as convenient as RealCADD.

I'm really sorry my suggestion has been so troublesome. I do think that one should consider PE, PC and PI as secondary snap functions, so it's not such a bad thing if they have to be chosen only when required, rather than active all the time.

Edit 3rd Feb I made a small movie of the problem at http://whisstock.com/images/p_problem.mov What I was aiming to do was to draw a perpendicular from the inner line (with just P selected) to the end of the red line, selecting E as i drew it – but the P line would not 'slide' along the inner line to allow me to do that. You can see I tried several times. And tried to draw a perpendicular from other lines. After I closed the drawing and re-opened it, it worked just as it should!

Sorry for the long delay, I was not satisfied with the new perpendicular feature in 4.80b1 and needed to think about it.
And busy too.

By default, the perpendicular attraction works like before the introduction of the new perpendicular feature.
But we can use the new feature and store the perpendicular object reference when one is found by hitting "alt+space".
After that, no other perpendicular attraction is searched, except if you hit again "alt+space" to erase the reference.

I think that this will fix the problems that you found.

Also, I have updated the accuracy of the drawings which is much better on retina screens.

But I can't seem to get the new perpendicular to work ... It works perfectly on lines that are vertical or horizontal drawing perpendiculars from E, C & I- but on lines that are at other angles it seems to draw a vertical or horizontal (from an E, C or I) rather than a perpendicular.

Maybe I'm not doing it right I've been letting it find an E, C or I and then holding down alt-space as I draw the line ... Is that correct??